A design that adapts to most smaller equipment. 
Three different radius surfaces for indicator readings.
Fits Shafts or hubs up to 2.8".
Can be rotated with only 3" shaft to base clearance.
Expands to 9".
"½" thick 
This model replaces the older Model A-500.   It is smaller and more compact to fit in very tight places.  It will fit most of the ANSI style pumps.